. Ecology. Amazon forest to Yungas premontane forest; on rocks, rarely found on logs, often along and in streams. Elevation. 230-900 m. Distribution. Bolivia: La Paz, Santa Cruz. World range: widespread in the Neotropics.
Callicostella rivularis is characterized by leaves grandually acute, somewhat irregularly toothed margins, but not coarse so, rarely swollen or bifid, smooth laminal cells, and setae roughened or papillose throughout.
Specimens. La Paz: Fuentes et al. 4065 (LPB, MO, USZ); Santa Cruz: Fuentes C. 179 (MO, USZ).